Both players, clearly, were serving well. But their ground strokes were near-perfect, too. They made almost no mistakes. Isner remembers feeling so happy with his game that “it’s hard to explain. I never thought about technique. I had no dark thoughts in my mind. I was just swinging away and the balls were going in - no matter if it was a big point, or whatever. It was crazy.”

Mahut, meanwhile, recalls an almost spiritual dimension to his play. “When we got into the money-time at 6-6 [he says ‘money-time’ in English], there was only John, myself, and my team. No one else. I didn’t hear the crowd. There was only the present time. I didn’t think about the point before, or the point after. I just stayed in the moment. I had absolutely no fear. The level of focus and awareness I had was so high. Normally, you don’t keep up for a long time. But that moment - I kept it for a long time.”

Mahut’s enjoyment, he says, was triggered by more than competition. After the many frustrations in his career, his pleasure came from fulfilling his potential. In this regard, his experience recalls Jean Bobet, the French cyclist of the 1950s, who wrote about experiencing “La Volupte” - the rare and sensual state of perfect riding. “La Volupte,” wrote Bobet, “is delicate, intimate, and ephemeral. It arrives, it takes hold of you, sweeps you up then leaves you again. It is for you alone. It is a combination of speed and ease, force and grace. It is pure happiness.”

How did it feel, to play tennis like that? “It was the biggest moment of my life,” says Mahut, gravely. “It was magical.”

Roger Federer has spent longer as a “still” athlete than any great player I can remember. You could even argue that it’s one of the signs of his greatness. Other top players hit the “still” moment, hang around for a little longer, and then whoosh, they’re gone, broken up into memorial clips and Hall of Fame inductions, classic rock bands who’ve sold their copyrights. Federer, after three straight years of diminished results — 11 to 12 singles titles a year from 2004 to 2006, then eight in 2007, and four to five every year since — is … well, still really amazing. He’s still near his best, which means he’s still playing some of the best tennis the world has ever seen. If anything, he’s improved his serve to compensate for what’s maybe been a slight decline in his movement and shot-making — although, as McEnroe pointed out during the French Open, his movement is “still great.” Heading into Wimbledon, historically his best tournament, he warmed up at the French by sensationally ending Djokovic’s 41-match winning streak and playing as well as Paris has ever seen him play against Nadal.

But because he’s been “still great” for so long — because we keep seeing the end coming, even if it never actually comes — Federer has also acquired an aura of weird sadness over the past few years that’s hard to reconcile with the way we used to think about him.

Speaking of sports, Grantland, and Federer, Bill Simmons said of Lionel Messi earlier this year that “he’s better at soccer than anyone else is at anything”. That’s a pretty short list but got me wondering, if you expanded the criteria slightly, who else might join Messi on the “better at their sport than almost anyone else is at anything at some point in the past 5-6 years”. Off the top of my head, possible candidates include Roger Federer, Usain Bolt, Michael Phelps, Lindsey Vonn, Tiger Woods, Marta, Shaun White, Jimmie Johnson, and Annika Sörenstam. I don’t know much about hockey, but maybe Alex Ovechkin? No basketball, baseball, or football players on that list; Michael Jordan and Barry Bonds are the most recent candidates in basketball and baseball (please, don’t give me any of that LeBron crap) and I can’t think of any football player over the past 20 years who might fit the bill. Barry Sanders maybe? His team never won a lot of games and didn’t win championships, but man he was a genius runner.